PURPOSE: To reduce the load of a host-side computer and to improve through-put by transmitting an editing command to the host-side computer and controlling a row editor processing when a screen editor processing is executed in a terminal-side computer.

CONSTITUTION: When the screen editor processing is executed in the terminal- side computer 20, an editing command generation means 22 automatically transmits the corresponding editing command to the host-side computer 10 and controls the row editor processing of the host-side computer. Thus, an operator executes the screen editor processing with satisfactory operability by using the terminal-side computer 20, and the host-side computer 10 executes the row editor processing by using a half duplex interface.